The development of the cartridge ribbon in which the ribbon supply reel and take-up reel are contained within a cartridge has eliminated the need for a user to carefully thread the ribbon through the various guide members of a conventional typewriter. However, the use of the cartridge ribbon has resulted in a need for a simple and efficient means for lifting the cartridge ribbon from a lower position, in which the printed characters can be viewed to a raised, or printing position, in which the characters are formed. The dynamic problems faced by a cartridge ribbon lift apparatus are more complex than those faced by the conventional ribbon lift apparatus of a conventional typewriter due to the greater mass and greater inertia of the cartridge ribbon as compared with the relatively small segment of conventional ribbon which is raised and lowered in a conventional typewriter. In addition, there is a need for a simple and efficient means for maintaining the cartridge ribbon in the printing position for periods of repeat printing and rapid burst typing.
The prior art related to electric typewriters includes various examples of devices for raising and lowering typewriter ribbon elements. Examples of such devices may be found in U.S. Pat. No. 890,037 to J. Felbel, U.S. Pat. No. 1,889,315 to E. H. Henderson, and U.S. Pat. No. 4,053,043 to D. R. Deetz. U.S. Pat. No. 890,037 shows a ribbon lift device which includes a latch which raises a vibratory ribbon carrier to locate a selected portion of the ribbon in a printing position for repeat printing. U.S. Pat. No. 1,889,315 shows a ribbon lift device in which a solenoid remains energized during a repeat printing operation to hold a ribbon carrier in a printing position. U.S. Pat. No. 4,053,043 shows a ribbon lift device which includes an electronic latch circuit for holding a ribbon cartridge in a printing position for repeat printing.
Each of the above ribbon lift devices is characterized by the use of a relatively large number of component parts resulting in a relatively high overall level of complexity. This results in a relatively high manufacturing cost due to the need for careful manufacture of the various component parts, complex and costly assembly procedures, a need for careful adjustment and a need for costly assembly procedures.